Simconnect is not malware; it’s the unspoken official API by which the simulator communicates sim variables to external programs. This API has existed for the simulator since the early 2000s.
The simulator is a black box. No one can see what’s happening in this black box. However, SimConnect connects wires to this box, and each wire is labelled. Things like “True Airspeed”, “Indicated Airspeed”, “True Altitude”, “Visibility”, etc. With these wires exposed, other programs are now able to see what’s happening inside this black box.
No SimConnect, no wires, no 3rd party functions.
If you lost your sim installation, then either you accidentally damaged your installation or you got malware from elsewhere. Either way, SimConnect is not the reason your simulator could go missing.